紫外辐照接枝HEMA改性血液过滤用PBT无纺布的研究

研究了在紫外辐照条件下,以二苯甲酮(BP)为光敏剂,以甲基丙烯酸羟乙酯(HEMA)作为表面接枝物来改性血液过滤用聚对苯二甲酸丁二醇酯(PBT)无纺布,并对接枝改性后PBT进行了红外分析、扫描电镜观察、亲水性能测试.结果显示:红外图谱证实了HEMA在紫外辐照和光敏剂BP的引发条件下成功接枝到PBT 无纺布纤维表面,光敏剂...     

HEMA接枝CPP的合成及其性能

以甲苯为溶剂,过氧化二苯甲酰(BPO)为引发剂,采用甲基丙烯酸羟乙酯(HEMA)通过自由基聚合接枝氯化聚丙烯(CPP);考察了引发剂类型对接枝反应的影响;研究了反应时间、反应温度、BIN)用量、HEMA用量对接枝率及接枝CPP黏合性能的影响,并对接枝产物进行了傅里叶变换红外光谱分析。确定了较理想的工艺条件：反应温度为110℃．反应时间为5h,m(CPP)／m(HEMA)／m(BPO)为1．0：1．0：0．1。     

表面接枝PHAMA对硅橡胶亲水性能的影响

将透明质酸钠盐与甲基丙烯酸酐在40℃下反应6 h,合成透明质酸甲基丙烯酸酯(HAMA),再通过紫外光辐照接枝反应将聚HAMA(PHAMA)接枝到甲基乙烯基硅橡胶表面。傅里叶红外光谱、扫描电子显微镜和热重分析均表明PHAMA接枝成功,PHAMA接枝硅橡胶的表面接触角由硅橡胶的107. 5°减小到68. 7°,亲水性得到改善。     

HEMA接枝改性天然胶乳的制备及其粘接性能研究

以甲基丙烯酸羟乙酯(HEMA)作为天然胶乳(NRL)的接枝改性剂,采用乳液聚合法制备了NR-g-HEMA[HEMA接枝NR(天然橡胶)]胶乳;然后以此为基体,并以水溶性松香树脂为增黏树脂、邻苯二甲酸二丁酯(DBP)为增塑剂等,制备相应的NR-g-HEMA胶粘剂;最后,用该胶粘剂压制胶合板,并对胶合板的粘接性能进行了测定。结果表明:采用单因素试验法优选出制备NR-g-HEMA胶乳的最佳工艺条件为m(干态单体)∶m(NRL)∶m(引发剂)∶m(活化剂)∶m(交联剂)=20∶100∶0.2∶0.2∶0.1、反应时间为8 h和反应温度为16℃,此时相应胶合板的剪切强度(1.88 MPa)符合Ⅲ类胶合板的指标要求。     

HEMA接枝氯丁橡胶胶粘剂高温粘接强度的研究

以氯丁橡胶(CR)、甲基丙烯酸羟乙酯(HEMA)、过氧化二苯甲酰(BPO)、甲苯和乙酸乙酯等为原料,制备了HEMA接枝氯丁橡胶溶液;然后在接枝氯丁橡胶溶液中,加入叔丁基酚醛树脂-氧化镁螯合型化合物、氧化锌、防老剂和多亚甲基多苯基多异氰酸酯(PAPI)等混配制得氯丁橡胶胶粘剂。着重研究了引发剂BPO用量对氯丁橡胶溶液黏度、分子量、接枝率的影响,以及PAPI用量对氯丁橡胶胶粘剂在常温和100℃下拉伸剪切强度的影响。研究结果表明:随着BPO用量的增加,氯丁橡胶溶液的黏度和分子量逐渐减小,而HEMA接枝氯丁橡胶溶液的黏度和接枝率均呈现先增后减的趋势;当BPO用量为0.4份时,HEMA接枝氯丁橡胶溶液的黏度相对最大(3 050 m Pa·s)、接枝率最高(10.2%);当PAPI用量为5份时,氯丁橡胶胶粘剂在室温和100℃下的拉伸剪切强度均相对最大,分别达到了2.41和1.88 MPa。     

脱氢型室温硫化(RTV)硅橡胶气泡生成影响因素的研究

研究脱氢型室温硫化(RTV)硅橡胶气泡生成影响因素,包括催化剂、交联剂和填料.催化剂用量和类型显著影响硅橡胶凝胶固化速度和发泡速度,进而影响硅橡胶的微观形态.随催化剂用量增加,产生气泡增多.交联剂用量增加,硅橡胶的凝胶时间变短,产生气泡增多.填料对硅橡胶气泡的产生也有一定影响.     

聚合松香与HEMA的酯化及其自聚研究

以聚合松香(PR)和甲基丙烯酸-β-羟乙酯(HEMA)为主要原料,两者酯化反应后得到PRH(酯化物);然后采用自由基聚合法得到PPRH(PRH的自聚物)。研究了单体比例和反应时间对酯化反应的影响,并采用FT-IR(红外光谱)法、GPC(凝胶渗透色谱)法、TGA(热失重分析)法和DSC(差示扫描量热)法等对产物的分子结构、Mr(相对分子质量)及其分布、热稳定性和Tg(玻璃化转变温度)等进行了表征。结果表明:当n(PR)∶n(HEMA)=1∶1.3、反应时间为3 h时,酯化率达到94.1%;不同产物的Tg大小为PR>PPRH>PRH;不同产物的Mr和热稳定性大小均为PR相似文献   

松香丙烯酸加成物与HEMA酯化及溴化反应研究

为了提高松香的附加值,利用松香和丙烯酸的Diels-Alder反应得到加成物(RA),RA进一步与甲基丙烯酸-β-羟乙酯(HEMA)反应得到酯化物(RAH),RAH再与液溴反应得到溴化物(BRAH)。以酸值为衡量指标优选出酯化反应的最佳工艺条件,并采用红外光谱(FT-IR)法和热失重分析(TGA)法对产物结构进行了表征。结果表明:酯化反应的最佳工艺条件为n(RA)∶n(HEMA)=1∶2.0,反应温度230℃,反应时间4 h,催化剂是ZnO,w(ZnO)=2%(相对于RA质量而言);RAH的热稳定性优于RA,BRAH具有一定的阻燃性能。     

缩合型RTV硅橡胶研究进展

介绍了室温硫化硅橡胶的基本情况。从基础聚合物、填料、硫化体系、其它助剂等几个方面综述了提高室温硫化硅橡胶性能的途径和方法,展望了室温硫化硅橡胶的发展前景。     

RTV硅橡胶胶粘剂

介绍了国内外 Ｒ Ｔ Ｖ 硅橡胶胶粘剂的概况,叙述单组分、双组分硅橡胶的品种、组成、性能和用途,展望硅橡胶的发展前景     

RTV防污闪涂料的研究

介绍了单组分RTV防污闪涂料的硫化机理、配制方法和基本组成，重点讨论了影响涂膜性能的各组分的功能及使用；并给出了产品的相关检测结果。     

In situ jute yarn composite with HEMA via UV radiation

Jute yarns soaked for 30 min in 2‐hydroxyethylmethacrylate (HEMA) + MeOH solutions at different proportions [1–20% HEMA in MeOH (v/v)] were irradiated in situ with a UV lamp for different periods. The treated jute yarns that were washed in acetone after the irradiation to remove the unused excess monomer HEMA gained about 10% polymer loading with enhanced tensile strength (80%) and elongation (95%). The tenacity was not further increased by incorporation of a minute amount (1%) of novel additives into the HEMA + MeOH solutions, but elongation was enhanced up to 140% when the additive urethane acrylate (1%) was mixed with the solution. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 841–846, 1999     

紫外光辐照聚丙烯膜接枝丙烯酸的研究

在水性体系中，通过紫外光辐照丙烯酸（AA）接枝到聚丙烯膜表面。考察了引发剂二苯甲酮（BP）用量、AA的体积分数、辐照时间、反应温度对接枝率的影响，以及不同接枝率下接枝膜对水接触角的变化。结果表明。接枝率在辐照时间为7min，AA体积分数为55％，BP用量为0．075g及反应温度为60℃时达到最大值。     

紫外光固化二氧化硅/丙烯酸酯亲水杂化薄膜

紫外光照射下制备了用于改善玻璃表面亲水性的二氧化硅/丙烯酸酯透明杂化薄膜,其水接触角小于5°,具有优异的亲水性。讨论了反应时间、反应温度、丙烯酸羟丙酯用量和正丙醇用量与薄膜亲水性的关系。通过SEM对薄膜表面形貌进行了研究,发现薄膜具有多孔结构,SiO₂溶胶粒子均匀分布在膜层中。研究表明,以硅溶胶（ml）与丙烯酸羟丙酯（mol）配比为50∶0.15在40℃时反应1 h制备杂化溶胶,且涂膜液用20%（质量）正丙醇稀释时所制备的杂化薄膜亲水性最好。     

Adhesion Improvement by UV Grafting onto Polyolefin Surfaces

High Density Poly(ethylene) (HDPE) and Poly(propylene) (PP) were subjected to several surface treatments, namely UV grafting of hydroxyethylmethacrylate (HEMA), plasma deposition of HEMA and oxygen plasma treatment. Treated surfaces were subjected to two post-treatment routines (extraction with ethanol and high temperature aging). The effect of these treatments on the adhesion of HDPE and PP to epoxy coated studs was evaluated by a pull test. No adhesion at all was recorded on untreated samples. On the other hand, all the treatments yield high bond strength in the case of HDPE: an average bond strength of about 290 kg/cm² and of about 200 kg/cm² was observed after UV grafting and plasma treatments. The treated samples were practically insensitive to post-treatments. As to PP, which undergoes chain scission in plasma, it is best treated by the comparatively milder conditions of UV grafting, which yields an average bond strength similar to that observed on HDPE. O₂ and HEMA-plasma-treated PP show a mean bond strength close to 50 kg/cm², and are deeply affected by the post-treatment routines.     

Adhesion Improvement by UV Grafting onto Polyolefin Surfaces

High Density Poly(ethylene) (HDPE) and Poly(propylene) (PP) were subjected to several surface treatments, namely UV grafting of hydroxyethylmethacrylate (HEMA), plasma deposition of HEMA and oxygen plasma treatment. Treated surfaces were subjected to two post-treatment routines (extraction with ethanol and high temperature aging). The effect of these treatments on the adhesion of HDPE and PP to epoxy coated studs was evaluated by a pull test. No adhesion at all was recorded on untreated samples. On the other hand, all the treatments yield high bond strength in the case of HDPE: an average bond strength of about 290 kg/cm² and of about 200 kg/cm² was observed after UV grafting and plasma treatments. The treated samples were practically insensitive to post-treatments. As to PP, which undergoes chain scission in plasma, it is best treated by the comparatively milder conditions of UV grafting, which yields an average bond strength similar to that observed on HDPE. O₂ and HEMA-plasma-treated PP show a mean bond strength close to 50 kg/cm², and are deeply affected by the post-treatment routines.     

微电子中先进复合材料抗紫外辐射研究

采用溶胶-凝胶法制备了纳米碳化硅(S iC)聚/酰亚胺(PI)复合材料,研究了纳米碳化硅的加入量对复合材料紫外光吸收和抗吸水性能的影响。结果表明,随nano-S iC用量的增加,nano-S iC/PI复合材料的吸水率有所下降,但对紫外光吸收明显增加,热解温度逐渐升高。     

Role of sand on curing of partex surface by UV radiation

A partex surface was modified by a UV‐curing system with epoxy acrylate (EB‐600). A set of formulations was prepared with oligomer and the trifunctional monomer trimethylol propane triacrylate in different combinations of percentages (1–5%) of sand to study the role of sand in various physical properties of UV‐cured thin films, as well as partex surfaces. Increased pendulum hardness (PH), gloss, adhesion, and abrasion values were obtained by the addition of sand into the partex surfaces. The best results were obtained with the formulation containing 3% sand. An enhanced PH and a decreased percentage of gel content of the UV‐cured film was observed with an increase of the sand concentration. A simulated weathering test was performed with partex surfaces cured by a formulation containing 3% sand in the base coat. The losses of the physical properties were found to be lower over the surface treated with the formulation containing sand. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2385–2392, 2002     

等离子体活化硅橡胶表面紫外接枝N-乙烯基吡咯烷酮

以等离子体活化硅橡胶,然后采用紫外光接枝法将N-乙烯基吡咯烷酮接枝于硅橡胶,同时使其自聚为稳定存在于橡胶表面的聚乙烯基吡咯烷酮。通过测定水接触角、红外光谱、X射线光电子能谱、扫描电镜等方法分析硅橡胶改性前后的表面变化。结果表明,改性后硅橡胶表面携带的新官能团和元素均带有聚乙烯基吡咯烷酮的特征,表明其与硅橡胶基质有较为牢固的化学键相连;硅橡胶表面的水接触角从改性前的110°降至改性后的18°,亲水性能改善明显。     

单组分缩合型室温硫化氟硅橡胶胶粘剂的研制

研究了羟基封端聚甲基三氟丙基-二甲基硅氧烷的合成方法,讨论了合成反应中催化剂用量对聚合反应的影响,并以此为主体材料制备了单组分室温硫化氟硅橡胶胶粘剂。试验结果表明,该聚合物有较好的耐油性能。